Sealing elements of this type have been known from, e.g., DE 196 34 444 A1 and are used in many areas of mechanical engineering, e.g., in automotive engineering. The above-mentioned document discloses a ball connection arrangement, in which an overpressure relief device is present, which is designed in the manner of a valve. An opening in an elastic sealing element, which opening connects the interior of a lubricant chamber to the outside air, is covered by a retaining ring here. If the pressure inside the lubricant chamber rises above a predetermined value as a consequence of a rise in the temperature of the lubricant, the pressing forces of the retaining ring are no longer sufficient to close the connection opening of the sealing element, so that lubricant can escape between the retaining ring and the sealing element at a corresponding overpressure.
The design of the overpressure relief structure disclosed in the document cited is disadvantageous because the retaining ring needed to seal the relief opening is displaceable in relation to the sealing element and also must be made as a slotted ring for reasons of mounting. Due to these properties dictated by the design, it may happen that the slot of the retaining ring is positioned exactly over the opening for relieving the overpressure. The consequence of this is that lubricant can escape unhindered to the outside even under normal pressure in the lubricant chamber or there is a possibility that contaminants can enter the lubricant chamber from the outside. Moreover, such retaining rings tend to fatigue or to have their function reduced at least partially, e.g., due to corrosion.